(CNN) -- What motivated an American soldier to allegedly open fire and kill 16 innocent Afghan civilians in cold blood? No one knows at this point. The soldier, an Army staff sergeant, seems to have acted alone, and he turned himself in to authorities after the shooting rampage. What we do know is that he had been injured in an accident while deployed to Iraq in 2010. Despite being diagnosed with traumatic brain injury, he was found fit for duty.

It's common for the military to evaluate service members for fitness for duty. The most important question asked is: Can the soldier safely and effectively perform his job from a mental health or neuropsychological standpoint?

More than a million individuals suffer a traumatic brain injury each year in the United States. Many of these people have experienced problems processing complex information. However, the execution-style killing of innocent people is not something that people with a traumatic brain injury would carry out. So while it's possible that "brain damage" is a contributing factor, it is unlikely to explain the slayings.

As the military community mourns the tragic loss of three Marines, that same community must be stunned by the violence that occurred at one of its most revered military bases.

Quantico Marine Corps Base is located in Virginia just south of Washington D.C. and is a key national security training location. The Quantico base, started during World War I, has played an important role in the training of generations of Marines as well as setting military doctrine for America’s battles and security parameters for our embassies abroad.

To listen to the somber reports coming from the base — that an active duty Marine fired his weapon on his fellow Marines with hostile and deadly intent — directly violates the culture of Marines to the core at a geographical location that many consider its epicenter of military dogma.

The Use of Mental Health Professionals in Coerced Interrogations: Ethico-Legal IssuesEarle Mack School of Law
Drexel University
March 20, 2009
9:00 AM - 12 Noon

A symposium on the legal and ethical issues in using mental health professionals in coerced interrogations, with a focus on their involvement in interrogating detainees at Guantanamo Bay.More information ...

Eric Zillmer, Athletic Director at Drexel University, as well as a Professor of Neuropsychology at the school and a clinical psychologist, has also been thinking a lot about how to convey to everyone on his staff the role they play in keeping children safe. "Having been an athletic director for 15 years and also being a behavioral scientist, creating a culture is really what I want to do," he says. "I believe you do that both from the top-down and bottom-up. I want to build a community where people care about each other, so I have to be the leader and live by those principles. But it also comes down to people talking with and supporting each other, the same way coaches build their teams.

One key part of building from the bottom up, Zillmer says, is to empower everyone to feel responsible for protecting minors. When talking to his staff, he uses this example: "If a child is visiting your house, you want to know where they are, what they are they doing, and that they're safe," he says. "As a parent, this is something you do intuitively and automatically. I told everybody we need to do the same thing here and make sure we always know what's going on when we have minors around. You can't just assume everything is okay."